Industrial truck



May 6, 1952 N. M. LAWLESS INDUSTRIAL TRUCK 6 Sheets-Sheet 1 OriginalFiled June 1, 1948 Fl 5. 8 a INVENTOR. NATHAN M. LAWLESS Fla-7 BY AyahATTORNEY 6 Sheets-Sheet 2 N. M. LAWLESS INDUSTRIAL TRUCK 11 INVENTOR.

AT T OPNE Y 7a NATHAN M. LAWLESS BY May 6, 1952 Original Filed June 1,1948 May 6, 1952 N. M. LAWLESS INDUSTRIAL TRUCK 6 Sheets-Sheet 5Original Filed June 1, 1948 2 M P m [fi fl J W L F H aw? i a 6 2 i x v kw 8 M 4B 5 m 5 1 a2 Q Q m b an Hi 9 m. 0? J? 2 W U. H w v MH/ww I; x I.M a a K M a v fi um... o a 9 n i w E w m 3. l 8 4 1 w U My a mu 8 b L6 5A J n L U A 1 4 m 2 1 F ATTORNEY N. M. LAWLESS May 6, 1952 INDUSTRIALTRUCK 6 Sheets-Sheet 4 Original Filed June 1, 1948 IN V EN TOR.

11 NATHAN M LAWLESS FIGS A TTOPNE Y y 6, 1952 N. M. LAWLESS 2,595,959

INDUSTRIAL TRUCK Original Filed June 1, 1948 s Sheets-Sheet e ATTORNEYPatented May 6, 1952 INDUSTRIAL TRUCK Nathan M. Lawless, MuskegonHeights, Mich., assignor to The Baker-Raulang Company, Cleveland, Ohio,a corporation of Ohio Continuation of application Serial No. 30,329,June 1, 1948. This application August 17, 1950,

Serial N 0. 180,014

19 Claims.

This invention relates to an industrial truck, more particularly anindustrial truck having an elevating member for stacking bodies (boxes,cartons, crates, filled bags and the like), and carrying out loading andunloading operations in plants, warehouses, docks and storage areas. Toprovide in a truck of this type an elevating member which may be raisedvarying heights and thus be adapted to a wide range of operatingconditions, the elevating member is slidably mounted on a plurality ofinner and outer telescopically related guides, which, when in normalposition (that is, in side-by-side relation with the elevating member inits down position), permit the truck to be driven through doorways,openings and other areas having low overhead conditions, but arerelatively movable endwise, that is, the inner guides are extensiblerelative to the outer guides to enable the elevating member to travel toand from elevations or levels above the height of the outer guides.However, in all trucks having guides operable in this manner, of which Ihave knowledge, the operating means for the elevating member and theguides therefor are inter-related, so that when. power is ap- 7 plied toraise the elevating member from its down position to an elevatedposition or level or in the reverse direction, the inner guidessimultaneously move in the same direction, although at a slower speed ascompared to that of the elevating memher. It will thus be observed thatthe operation of raising the elevating .member to any desired level iseffective to move the inner guides above or beyond the upper end of theouter guides, so that stacking, loading and unloadin operations infreight cars, boats, trailers, warehouses having low ceilings, lowoverhead members or roofs and other areas where the overheadapproximates the height of the outer guides for the elevating member,cannot be carried out.

One object of the invention is to provide, in a truck, having anelevating member movably supported by outer guides and inner extensibleguides, improved power means for raising the elevating member,automatically operable to initially control the movement of theelevating member relative to and independently of the inner guides toand from levels within the upper ends thereof when outer and innerguides are in side-by-side relation and thereafter effect movement ofthe extensible guides above the upper ends of the outer guides, wherebythe elevating member may be raised to higher levels.

Another object of the invention is to provide, in an elevating truck,improved power means for raising the elevating member, operable to movethe latter a predetermined distance from its down position upwardlyrelative to and independently of its guides, whereby stacking, loadingand unloading operations at or within levels which approximate theheighth of the inner guides may be carried out. I

Another object of the invention is to provide, in an elevating truckhaving outer guides and inner extensible guides for the elevatingmember, improved power means for raising the elevating member capable ofinitially moving it to a predetermined level relative to andindependently of its inner guides and automatically operable to move theextensible guides and guide the elevating member to higher levels.

Another object of the invention is to provide an improved fluid operatedmechanism for the elevating member of an industrial truck operable toeffect movement of the elevating member to and from a predeterminedlevel and thereafter to efiect relative movement of the guides for theelevating member and movement of the latter to higher levels.

Another object of the invention is to provide an improved fluid operatedmechanism for raising and lowering the elevating member on an industrialtruck, the mechanism consisting of inter-related fluidactuated membershaving connections with a source of fluid supply under pressure andoperable (a) to initially raise the elevating member to and from apredetermined level and intermediate levels independently of its guidesor (b) eiiect relative movement of the guides and elevating member,whereby the latter may be raised to a higher level.

Other objects of the invention will be apparent to those skilled in theart to which my invention relates from the following description takenin connection with the accompanying drawings, wherein Fig. 1 is a sideelevation of a truck embodying my invention;

Fig. 2 is a front elevation;

Fig. 3 is a view similar to Fig. 2 (enlarged), parts being broken away;

Figs. 3a and 3b are sections on the lines 3a3a and 311-31),respectively, of Fig. 3;

Fig. 3c is a section on the line 3c-3c of Fig. 4;

Fig. 4 is a section on the line 44 of Fig. 3;

Figs. 5 and 6 are sections on the lines 5-5 and 6-5, respectively, ofFig. 3;

Fig. 7 is a section on the line 'I-! of Fig. 4;

Figs. 7a and 8 are fragmentary elevations on the lines 'Ia'la and 8-8,respectively, of Fig. 4; Fig. 8a is a side elevation of parts shown inFig. 8;

Fig. 9 is a front view, substantially similar to Fig. 3, showing theposition of the parts when the elevating member is moved to one level,parts being broken away;

Fig. 10 is a section on the line Ill-46 of Fig. 9, parts being brokenaway;

Fig. 11 is a view substantially similar to Fig. 9, but showing theposition of the parts when the elevating member is raised to a higherlevel;

Fig. 12 is a section on the line I2I2 of Fig. 11;

Fig. 12a is a section on the line I2aI2a of Fig. 3;

Fig. 13 is a view substantially similar to Figs. 3, 9 and 11, butshowing a modified form of construction; and

Fig. 14 is a section on the line I4I 4 of Fig. 13, parts being brokenaway.

In the drawings, I indicates as an entirety a chassis mounted on frontand rear wheels 2, 3, respectively. The wheels at either the front orrear of the chassis I may be driven and also steerably mounted. Themounting of the driving mechanism for the driven wheels and the powersupply for the driving mechanism may be suitably supported on thechassis dependent upon the capacity of the truck and other factors. Asthese mechanisms and the mountings therefor form no part of the presentinvention and may be of any desired construction, illustrations of thesemechanisms are omitted. In the exemplified form of construction, acasing 4 on the rear end of the chassis I houses the power supply and acasing on the front end of the chassis I houses certain of the operatingequipment for the truck, the space between the casings 4, 5, beingutilized as the drivers station. I5 indicates as an entirety a fluidoperated elevating mechanism for an elevating member or load carrier Iadapted to engage loads at different levels, transport them to a placeof storage, shipment, assembly or other use and discharge them at thesame or a different level. The elevating mechanism 6 is preferablymounted to swing inwardly to facilitate transportation of loads on thecarrier I. In the form of construction shown, the outer guides 6a of theelevating mechanism are provided with rearwardly extending arms 8 formedat their outer ends with openings 81]; which rotatably fit a hollow axle211 for the front wheels 2 (see Fig. 4). Where the wheels 2 are driventhe hollow axle 2a forms a housing for the shafts which. are drivinglyconnected with the wheels 2. The elevating mechanism 6 is preferablyswung from its normal or vertical position inwardly and outwardly byfiuid operated means consisting of a cylinder 9 suitably supported inthe casing 5 and having a reciprocatable piston connected by a rod 9a totoggles 9b which in turn are pivotally connected to fixed brackets 90mounted in the casing 5 and a yoke II], the opposite end portions of theyoke being firxed (preferably welded) to the inner side walls of theguides 6a (see Fig. 6). The supply of fiuid to the piston is controlledby a suitable three-way valve of well known construction, operated by alever 9:0.

The elevating mechanism 6 comprises the following: 6a indicates a pairof outer guides (already referred to) of channel shape in cross sectionfixedly connected at their lower ends to a base II, and connected attheir upper ends by a cross member Ila. I2 indicates a pair of innerguides of channel shape in cross section slidably fitting the guides 6aand connected together at their upper ends by a cross member I2a. Theguides 6a, I2, are of substantially equal length, so that when the loadcarrier I is in its down or lowest position (Figs. 1, 2, 3 and 4), theupper ends of the inner guides I2 do not extend beyond the upper ends ofthe outer guides 6a. The opposite side walls of the inner guides I2 areengaged by upper and lower rollers I3 to movably support the carrier Ithereon. The carrier 1 may be of any desired construction, but is shownas consisting of-a wall Ia provided with rearwardly extending plates Ibeach supporting upper and lower stud shafts 10 on which the rollers I3are mounted. The upper end of the wall Ia adjacent its opposite sidesand intermediate the latter' is provided with brackets I4 in which a rodMe is mounted. The rod I4a extends through openings formed in or hollowbosses provided on the upper ends of the vertical legs of the forks I5to support the latter on the wall Ia. and provide for adjustment of eachfork I5 transversely thereof. I6 indicates a piston, which is preferablyhollow and having upper and lower heads I6a, IBb, respectively. Thelower head IE1: is rigidly secured to a plate I6e, which in turn isbolted or otherwise secured to the base II. The upper end of the pistonI6 is provided externally with an annulus I5d, the outer wall of whichis cut away as shown at I6e (Fig. 3a) for a purpose later set forth. Nindicates a cylinder telescopically related to the piston I6 andprovided internally at its lower or open end with a ring I'Ia slidablyfitting the piston I6, the ring Na and annulus I6d providing a fluidchamber between the piston I6 and cylinder I1. The cylinder I1 ispreferably substantially equal in length to the iston I6 and when innormal position, (that is, when the carrier I is in its down position,as shown in Figs. 3 and 4) the head IIx of the cylinder I'I engages theupper end of the piston I6. The upper end of the cylinder I6 extendsabove the head I6a to form a space I611: between the latter and the headHas, the extended end of the cylinder I6 being formed with slots I6a'(see Fig. 3a) to permit flow of liquid from the chamber into the spaceI632, when the cylinder I1 is in normal position, as shown in Fig. 3.The side wall of the cylinder I1 is formed with an opening I'Ib for thesupply of fluid (preferably liquid such as oil) under ressure thereintoand discharge of the liquid from the cylinder dependent upon theoperation of a suitable valve, which is operated by a lever I837,connected with the opening I'Ib by piping I8 having a flexible sectionI8a to compensate for the movement of the carrier I (Fig. 4). Thecylinder I'I, adjacent its lower end, is provided with diametricallyrelated laterally extending supports I9 on which the lower ends ofupright members I9a are supported. The upper end of each upright memberI911 is bifurcated to accommodate a sprocket 20, which is engaged by achain 20a. One end of each chain 20a is suitably anchored to the baseII, whereas its opposite end is secured to a bracket 20b fixed to andextending inwardly from the adjacent inner guide [2. Accordingly, whenfluid is supplied to the cylinder II, as later set forth, to move itendwise upwardly, the guides I2 will be moved upwardly varying desirabledistances, one position of the guides being shown in Fig. 11.

2|, 22, indicate inner and outer telescopically related cylinders, theinner cylinder 2| slidably fitting the cylinder II, each cylinder 2I andII being movable relative to the other or simultaneously relativelymoved as later set forth. The upper end of the outer cylinder 22 isprovided with a plate 22a which is bolted or otherwise secured to thecross bar l2a. The inner wall of the cylinder 22 adjacent its lower oropen end is provided with an annular band 22b supported in the cylinderby a collar 22c and slidably engaging the cylinder 2 l, whereas theouter wall of the inner cylinder 2| is provided with an annulus 2|awhich co-operates with the band 22b to provide an annular chamberbetween the cylinders 2|, 22. The inner cylinder 2| inwardly of itsupper end is provided with a head 2 lb which provides a space 2|:cbetween the head 2|b and the plate 22a, within the cylinder 2| when thelatter is in normal position, as shown in Fig. 3. The end wall of thecylinder 2|, outwardly of the head 2|b, is formed with slots 2|c and theouter side of the annulus 2|a is cut away as shown at 2 Id (Fig. 3b), topermit now of liquid from the chamber between the cylinders 2| 22, intothe space 2 lat. The side wall of the cylinder 22, inwardly of the band22b is formed with an opening 22$ for the supply of the fluid underpressure thereinto and discharge of the fluid from the cylinder,dependent upon the operation of the lever |8:c for thevalve, the opening22.1."being connected by a section of hose |8b leading from the pipingl8 (Fig. 4). 23 indicates a pair of chains connected at their inner endsto the lower portion of the wall la of the carrier 1. The chains 23extend upwardly at diametrically opposite sides of the piston l6 andcylinders l1 and 22 and engage sprockets 24 rotatably supported on studshafts 24a fixed to the opposite sides of the cylinder 22. From thesprockets 24 the chains 23 extend downwardly and engage sprockets 25rotatably mounted on stud shafts 25a fixed to the opposite sides of thecylinder 2| below the open end of the cylinder 22. From the sprockets25, the chains 23 extend upwardly, their outer ends being suitablyanchored at 23a to diametrically opposite sides of the cylinder 22,

Operation: The relatively movable cylinders ll, 2|, 22, are shown (Figs.3 and 4) in normal position with the guides Go, 2, in side-by-siderelation and the carrier 1 in its down position. The chambers betweenthe piston l6 and cylinder l1 and between the cylinders 2|, 22, arefilled with the pressure medium. The fluid under pressure is supplied toand through the pipe l8 and hose sections l8a, l8b, from a single sourceof supply, namely, a suitable motor driven pump drawing the liquid froma reservoir I8" upon opening of the control valve by operation of thelever I850. Accordingly, liquid pressure is supplied to the chamberbetween the piston l6 and cylinder l1 and to the chamber between thecylinders 2|, 22, but by reason of the fact that the area of the head2|b for the cylinder 2| is greater than that of the head Ila: for thecylinder H, the supplied pressure will be effective initially to movethe cylinder 2| downwardly relative to the cylinders l1 and 22, therebycarrying with it the sprockets 25. As the pressure is applied betweenthe head 2|B and plate 22a, the weight of the carrier 1 and any loadthereon is sustained by the cylinder 22, and the outer ends of thechains are anchored at 23a to the cylinder 22, the movement of thesprockets 25 with the cylinder 2| downwardly will transmit a pull on thechains 23, which will reeve about the sprockets 25 and 24, and raise theload carrier 1 to a predetermined level or any selected intermediatelevel but independently of the extensible or inner guides l2,

without raising the latter (see Figs. 9 and 10) If the lever lilacismoved to its other position, the load carrier will gravitate to itsdown position, cylinder 2| will move upwardly due to pull in theopposite direction on the chains 23: liquid supplied to the chamberbetween the piston l6 and cylinder I! will be retained therein, but theliquid in cylinder 22 will be forced out or discharged therefrom throughpipes l8b, l8, and the control valve to the reservoir. The downwardmovement of the cylinder 2| is limited by the engagement of its head orend wall 2 lb with the upper end of the cylinder H (see Fig. 9), thehead lla: of which is in engagement with the upper end of the piston l6.In the arrangement disclosed, (a) the length of the piston l6 has apredetermined relation to the length of the guides 6a, l2, so as tolimit the endwise movement of the cylinder 2| to one-half the length ofthe guides 6a, l2, and (b) the load carrier 1 is actuated at a speedtwice that of the cylinder 2| and therefore may be moved twice thedistance moved by the cylinder 2|, in each operation of the controlvalve to raise or lower the load carrier. Accordingly, upon supply ofliquid to operate the cylinder 2| from its normal position (Figs. 3 and4) to the full limit of its downward movement, the load carrier 1 willbe raised to the position shown in Figs. 9 and 10. It will therefore beobserved that loading and/or unloading operations may be carried outwhere overhead conditions are such as to prevent the inner guides l2 toextend above the upper ends of the outer guides 6a.

However, where these overhead limiting condition do not prevail and thesupply of liquid under pressure is continued following the engagement ofthe cylinder 2| with the cylinder I1, as above set forth, the continuedsupply of liquid into the chamber between the piston l6 and cylinder I!will exert pressure on and move the latter upwardly. As the head 2 lb ofthe cylinder 2| is in engagement with the head of the cylinder l1, andthe cylinder 22 between the plate 22a and head 2 lb is filled with oil,upward movement of the cylinder l'l will move the cylinder 2| upwardlyto its upper or normal position. As the uprights |9a are connected tothe cylinder l1 and sprockets 20 are carried by the uprights, upwardmovement of the cylinder l'l will effect a pull on the chains 20a toraise the guides I2 upwardly beyond the guides 6a and thus guide thecarrier to a higher level and the guides |2 being connected with thecylinder 22 the latter will move upwardly therewith. As the chains 20aare connected at their inner ends to the base II and reeved around thesprockets 20, the guides l2 and cylinder 22 will move upwardly at aspeed twice that of the cylinders l1 and 2|. Due to this difference inspeed movement between the cylinders 2| and 22, the sprockets 24 willmove relative to the sprockets 25 to effect a reeving of the chains 23around the sprockets and move the carrier 1 on the guides l2 to a higherlevel. If the lever |8x is moved to its opposite position, wherebyliquid pressure is relieved, the carrier 1, guides I2 and cylinders 22,2| and I! will gravitate downwardly to the position shown in Figs. 9 and10, such movement effecting a reeving of the chains 2323 and 2|la2fla inthe opposite direction, whereas the carrier I will continue to gravitateto the position shown in Figs. 3 and 4, the reeving of chains 23--23during this gravitational movement of the carrier 1 serving to move thecylinder 2| upwardly to its normal or uppermost position. By operationof the lever |8:c, the carrier I in moving in either direction may bestopped at any desired level within the limits of its travel and held atsuch level and thereafter moved in either direction.

From the foregoing description it will be seen thatwhile the length ofthe guides 60, I2, is determined by the overhead conditions existingwhere the truck is to be used, the truck may be operated for carrying,raising and lowering loads at loading and unloading stations at theplace of use where the overhead space permits the extensible or innerguides l2 to be endwise raised above the outer guides 6a.

From the foregoing description it will be observed that I providebetween the lower ends of the outer guides and the upper ends of theextensible or inner guides upper and lower fluid operatedpiston-cylinder couples in co-operative relation and having adiiferential operating relation and that the couples are simultaneouslysupplied with liquid under pressure from a single source of supply. Dueto the differential relation between the couples, (a) the upper coupleis initially operable'to effect the upward and lowering movements of theload carrier to or within a predetermined elevation or level and ('22)both couplesare successively operable, whereby the load carrierjmay beraised to and from levels above the predetermined level, theserespective operations being carried out by the operation of the valve I8shown in Fig. 12a. The construction is greatly simplified and readilyand rapidly operated due to the fact that only one source of liquidsupply and one valve are required to operate the load carrier within thepredetermined level or to higher levels by the operator and that whilethe truck may be used under restricted overhead conditions, it isequally adapted to a wide range of conditions, without removal,replacement or adjustment of any parts of the elevating mechanism ortruck construction.

The valve or valves for controlling the supply of liquid to thecylinders 9, I! and 22 may be of any desired form of construction, oneexample of which is shown in Fig. 12a, wherein the casing of the valveI8 is mounted on the reservoir I8" (see Fig. 3), the valve element I issuitably connected to the lever 9:1: and the valve element l0| issuitably connected to the lever 18.1. In supplying liquid to thecylinder 9 to tilt the elevating mechanism 6, the lever 9:1: is operatedto move the valve element I00 outwardly; liquid under pressure issupplied by pipe ||l| a, which leads from the pump, to ducts l0|b, IUlc,lllld, to a pipe Illlzr, which has connections with the cylinder 9; byoperating the lever 93: to its other position, the elevating mechanism 6gravitates to its normal position and the liquid in the cylinder 9 flowsback through pipe llllr, ducts luld, lllle, to opening |0|f leading intothe reservoir l8. In supplying liquid to the cylinders l1 and 22, thelever Him is operated to move the valve element |0| inwardly; liquidunder pressure is supplied by the pipe Illla. to the duct IUIb, flowsthrough valve element IOI to the duct I02 which is connected to pipe I8;operation of the lever I81: to its other position, connects the duct I02with the duct llllle, so that in the movement of the cylinders 2|, orcylinders 2| and 22 to their normal positions, the liquid not retainedtherein flows back into the reservoir I8".

Figs.. 13 and 14 illustrate a modified form of construction wherein therate of movement of the load carrier, when being raised toand frompositions above the predetermined level, is increased relative to therate of movement of the cylinders l1, 2|, whereby loading and unloadingoperations at these higher levels are facilitated. In this form ofconstruction, the upper and lower fluid operated couples and the reevingconnections between the carrier 1 and cylinders 2| and 22 are similar toand operate in the same manner as like parts shown in Figs. 3 to 12,inclusive; also, the cylinder I1 is provided at diametrical sides withsupports IQ. for the uprights I9a, but the inner ends of the chains 20aare fixed to and extend downwardly from the supports I9 and reeve aroundsprockets 20a: suitably rotatably mounted on standards 20:1," fixed tothe base From the sprockets 203:, the chains 20a extend upward and reevearound the sprockets 28, their outer ends being connected to thebrackets 20b, as set forth in connection with the construction shown inFigs. 1 to 12, inclusive. By connecting the chains 20a to the supportsI9 on the cylinder I1 and extending them around the sprockets 209:, itwill be seen that when the fluid pressure is effective to move thecylinders l1 and 2| upwardl the load carrier moves three times as fastas these cylinders and hence speeds up the operations of loading andunloading at the higher levels which require a longer travel of thecarrier.

To those skilled in the art to which my invention relates many changesin construction and widely differing embodiments and applications of theinvention will suggest themselves without departing from the spirit andscope of the invention. My disclosures and the description herein arepurely illustrative and are not intended to be in any sense limiting.

This application is a continuation of my application filed June 1, 1948,Ser. No. 30,329, now abandoned.

What I claim is:

1. In a truck, the combination with a frame, of a pair of vertical outerguides mounted on said frame, a pair of inner guides telescopicallyrelated to said outer guides, a piston fixedly related at its lower endto the lower ends of said outer guides, a plurality of telescopicallyrelated, relatively movable cylinders, the lower cylinder beingreciprocatable on said piston and the upper outer cylinder beingconnected to said inner guides, a source of fluid supply under pressureconnected to said upper outer cylinder and said lower cylinder, a loadcarrier slidable on said inner guides, a flexible member connected atits inner end to said carrier and anchored at its outer end to saidupper outer cylinder, a reeving element for said flexible member mountedon said upper outer cylinder, a separate reeving element on the lowerend portion of one of the cylinders within the said'upper outercylinder, that cylinder carrying said separate reeving element beinginitially moved downwardly upon the supply of fluid pressure to' saidupper outer cylinder to raise said carrier relative to said innerguides, means actuated by said lower cylinder for moving said innerguides endwise relative to said outer guides, and a valve forcontrolling the supply of fluid under pressure into said upper outercylinder and into said lower cylinder.

2. In a truck, the combination with a frame, of a pair of vertical outerguides mounted on said framefit Pair of inner guides telescopicallyrelated to said outer guides, a piston fixedly related to the lower endsof said outer guides, a cylinder reciprocatable relative to said piston,upper telescopically related inner and outer cylinders, the innercylinderslidably fitting said reciprocatable cylinder and the outercylinder being connected to the upper end of one of said inner guides, aload carrier slidable on said inner guides, a flexible member connectedat its inner end to said carrier and anchored at its outer end to saidupper outer cylinder, reeving elements for said flexible memberrespectively mounted on said upper outer cylinder and on the lower endportion of said inner cylinder, means actuated by said lower cylinderfor moving said inner guides endwise relative to said outer guides, andmeans for supplying fluid under pressure into said upper outer cylinderand into said reciprocatable cylinder.

3. In a truck, the combination with a frame, of a pair of vertical outerguides mounted on said frame, a pair of inner guides telescopicallyrelated to said outer guides, a load carrier slidably mounted on saidinner guides, telescopically related upper and lower piston-cylindercouples, the piston element of said lower couple being connected at itslower end to the lower end of one of said outer guides, the cylinderelement of said upper couple being connected at its upper end to theupper ends of said inner guides and the piston element of said uppercouple being hollow and slidably fitting the cylinder element of saidlower couple, operating connections between said carrier and thecylinder and piston elements of said upper couple, operating connectionsbetween the cylinder element of said lower couple and said inner guides,and means for simultaneously supplying fluid under pressure to saidcouples, said couples having a differential relation effective toinitially move said carrier relative to and independently of said innerguides a predetermined vertical distance in advance of the verticalmovement of said inner guides.

4. In a truck, the combination with a frame, of a pair of vertical outerguides mounted on said frame, a pair of inner guides telescopically re'lated to said outer guides, a load carrier slidably mounted on saidinner guides, telescopically related upper and lower piston-cylindercouples, the piston element of said lower couple being connected at itslower end to the lower ends of said outer guides, the cylinder elementof said upper couple being connected at its upper end to one of saidinner guides and the piston element or" said upper couple being hollowand slidably fitting the cylinder element of said lower couple, areeving device exteriorly mounted on the upper end portion of thecylinder element of said upper couple, a reeving device exteriorlymounted on the lower end portion of said piston element of said uppercouple, a flexible member connected at its outer end to said carrier andto the cylinder element of said upper couple inwardly of its lower endand engaging said devices intermediate its ends, operating connectionsbetween the cylinder element of said lower couple and one of said innerguides, and means-for supplying fluid under pressure to said couples,said couples having a differential relation elTective to move saidcarrier along said inner guides a predetermined vertical distance inadvance of the vertical movement of said inner guides.

5. In a truck, the combination with a frame, of a pair of vertical outerguides mounted on said'frame, a pair of inner guides telescopically 10related to said outer guides, a load carrier slidable on said innerguides, and fluid operated means for raising said load carrier, saidmeans consisting of a piston fixedly related to the lower end of one ofsaid outer guides, a lower cylinder telescopically related to saidpiston and forming therewith a fluid chamber, an upper cylinderconnected to said inner guides and an intermediate cylindertelescopically related to said lower cylinder and said upper cylinderand forming with the latter a fluid chamber, a flexible member connectedat its inner end to said carrier and anchored at its outer end to saidupper cylinder, reeving elements for said flexible member mounted onsaid upper cylinder and on the lower end portion of said intermediatecylinder, means actuated by said lower cylinder for moving said innerguides for moving the latter endwise relative to said outer guides andmeans for supplying liquid under pressure into said upper cylinder andinto said lower cylinder.

6. In a truck, the combination with a frame, of a pair of vertical outerguides mounted on said frame, a pair of inner guides telescopicallyrelated to said outer guides, a load carrier slidable on said innerguides, and fluid operated means for raising said load carrier, saidmeans consisting of a piston fixedly related to the lower ends of saidouter guides, a lower cylinder telescopically related to said piston,the upper end of said lower cylinder having a head normally engaging theupper end of said piston and forming therewith a fluid chamber, an uppercylinder closed at its upper end and connected to one of said innerguides, an intermediate cylinder within said upper cylinder and formingtherewith a fluid chamber and arranged to slidably fit the outer wall ofsaid lower cylinder when moved downwardly, said intermediate cylinderbeing closed by a head at its upper end, a flexible member connected atits inner end to said carrier and anchored at its outer end to saidupper cylinder, reeving elements for said flexible member mounted onsaid upper cylinder and on the lower end portion of said intermediatecylinder, means connecting said lower cylinder to one of said innerguides for moving the latter endwise relative to said outer guides andmeans for supplying fluid under pressure into saidupper cylinder andinto said lower cylinder and arranged to initially move saidintermediate cylinder downwardly to raise said carrier independently ofsaid guides to a predetermined position and thereafter move said lowerand intermediate cylinders upwardly to raise said inner guides relativeto said outer guides and said carrier above said predetermined position.

7. In a truck, the combination with a frame, of a pair of vertical outerguides mounted on said frame, a pair of inner guides telescopicallyrelated to said outer guides, a load carrier slidably mounted on saidinner guides, telescopically related upper and lower piston-cylindercouples, the piston element of said lower couple being connected at itslower end to the lower end of one of said outer guides, the cylinderelement of said upper couple being connected at its upper end to theupper end of one of said inner guides and the piston element of saidupper couple being hollow and slidably fitting the cylinder element ofsaid lower couple, flexible members disposed at opposite sides of saidcouples and connected at their inner ends to said carrier and anchoredat their opposite ends to the opposite sides of the cylinder of saidupper couple,

reeving elements for said members diametrically mounted on the outerside of the cylinder of said upper couple, reeving elements for saidmembers diametrically mounted on the outer side of the piston element ofsaid upper couple, operating connections between the cylinder element ofsaid lower couple and said inner guides and means for simultaneouslysupplying liquid under pressure to said couples, said couples having adiiferential relation effective to initially move said carrier relativeto and independently of said inner guides a predetermined verticaldistance in advance of the vertical movement of said inner guides.

8. A truck as claimed in claim 6 wherein the length of said piston isproportioned to the length of said guides to limit the downward movementof said intermediate cylinder and raising of said carrier independentlyof said guides.

9. In a truck, the combination with a frame, of a pair of vertical outerguidesmounted on said frame, a pair of inner guides telescopicallyrelated to said outer guides, a load carrier slidably mounted on saidinner guides, a piston connected at its lower end to the lower end ofone of said outer guides, a cylinder slidably related to said piston andmovable upwardly relative thereto, a separate cylinder connected at itsupper end to one of said inner guides, a hollow piston in said separatecylinder and movable downwardly relative thereto and arranged totelescopically engage the outer wall of said first mentioned cylinder,operating connections between said carrier, said separate cylinder andsaid hollow piston, operating connections between said first mentionedcylinder and said inner guides, and means for applying fluid underpressure to each of said cylinders, a valve mechanism for controllingthe supply of fluid to said cylinders and arranged to move said hollowpiston downwardly to raise said carrier to a predetermined level and tomove said first mentioned cylinder and said hollow piston upwardly toraise said carrier to a higher level.

10. In a truck, the combination with a frame, of a pair of verticalouter guides mounted on said frame, a pair of inner guidestelescopically related to said outer guides, a load carrier slidablymounted on said inner guides, hydraulically operated means for raisingsaid carrier to a predetermined level independently of the guides andraising said inner guides and said carrier to a higher level, said meansincluding a cylinder connected to one of said inner guides, a pistonherein, operating connections between said carrier, cylinder and pistonarranged when the latter is moved downwardly to move said carrierupwardly to a predetermined level independently of said guides, a liquidpressure operated device connected to said inner guides for moving saidpiston in the opposite direction and said inner guides upwardly andthrough said operating connections raise said carrier to a higher level,and means for supplying liquid under pressure to said cylinder and tosaid device.

11. In a truck, the combination with a frame, of a pair of verticalouter guides mounted on said frame, a pair of inner guidestelescopically related to said outer guides, a load carrier slidable onsaid inner guides, upper and lower reeving devices, a support for saidupper reeving device fixedly related to said inner guides, a separatesupport for said lower reeving device, slidably mounted in said firstmentioned support, a flexible member connected at its inner end to saidcarrier and anchored at its outer end to said first mentioned supportand engaging said devices intermediate its ends, said separate supportbeing movable downwardly to effect a reeving of said flexible member,whereby said carrier is raised to a predetermined level independently ofsaid guides, a movable device having reeving connections with said innerguides and arranged when moved upwardly to move said separate supportupwardly and said inner guides and first mentioned support upwardly at afaster rate of speed relative to said separate support, to raise saidcarrier to a higher level, and means for successively moving saidseparate support downwardly and said movable device upwardly.

12. In a truck, the combination with a frame, of a pair of outer guidesmounted on said frame, a pair of inner guides telescopically related tosaid outer guides for movement endwise thereof, a load carrier slidableon said inner guides, upper and lower reeving devices, relativelymovable supports for said devices, the support for said upper devicebeing connected to said inner guides for movement therewith, a flexiblemember connected at its inner end to said carrier and anchored at itsouter end to the support for said upper device and engaging said devicesintermediate its ends, said support for said lower reeving device beingmovable downwardly to efiect a reeving of said flexible member and raisesaid carrier to a predetermined level independently of said guides, amovable device having reeving connections with said inner guides andarranged when moved upwardly to move said support for said lower reevingdevice upwardly and simultaneously move said inner guides and saidsupport for said upper reeving device upwardly and relatively to saidsupport for said lower reeving device to effect relative movementbetween said reeving devices, whereby said carrier is moved to a higherlevel, and means for successively operating the support for said'lowerreeving device downwardly and said movable device upwardly.

' 13. In a truck, the combination with a frame, of a pair of outerguides mounted on said frame, a pair of inner guides telescopicallyrelated to said outer guides for movement endwise thereof, a loadcarrier slidable on said inner guides, upper and lower reeving devices,a cylinder and a piston therein for supporting said devices,respectively, said cylinder being connected to said inner guides formovement therewith, a flexible member connected at its inner end to saidcarrier and anchored at its outer end to said cylinder and engaging saiddevices intermediate its ends, said piston being movable downwardly toeffect a reeving of said flexible member and raise said carrier to apredetermined level independently of said guides, a movable devicehaving reeving connections-with said inner guides and arranged whenmoved upwardly to move said piston upwardly and simultaneously move saidinner guides and said cylinder upwardly and relative to said piston toeffect relative movement between said reeving devices, whereby saidcarrier is moved to a higher level, and means for supplying fluidpressure to said cylinder and said movable device to successively movesaid piston downwardly and said movable device upwardly.

14. In a truck, the combination with a frame, of a pair of verticalouter guides mounted on the frame, a pair of inner guides telescopicallyrelated to said outer guides, a load carrier slidably mounted on saidinner guides, upper and lower reeving devices, relatively movablesupports for said devices, said upper support being connected to saidinner guides, a flexible member connected at its inner end to saidcarrier and anchored at its outer end to the support for said upperreeving device and engaging said devices intermediate its ends, amovable member having reeving connections with said inner guides formoving them upwardly, and mechanism for moving the support for saidlower reeving device downwardly into engagement with said movable memberand for moving said movable member upwardly to move the support for saidlower reeving device upwardly and through said reeving connections movesaid inner guides and the support for said upper reeving device upwardlyrelative to the support for the said lower reeving device, the downwardmovement of the support for said lower reeving device serving to raisesaid carrier to a predetermined level and relative upward movement ofsaid supports serving to raise said carrier to a higher level.

15. In a truck having a pair of substantially vertical outer guidessupported on the truck frame, a' pair of inner guides slidably mountedon said outer guides and movable endwise thereof, a load carrierslidably mounted on said inner guides, a hydraulically operatedmechanism consisting of a member mounted on the truck frame between saidpairs of guides, a plurality of concentrically related elements axiallydisposed and movable endwise of said member and formed with fluidconnections between them, one of said elements being provided withdiametrically disposed reeving devices, flexible members engaging saidreeving devices and connected to said load carrier, and fluid underpressure supply means controlled by a single valve and connected to thespaces between said elements and arranged to apply pressure to the upperend of that element provided with said reeving devices and the adjacentelement for moving said first element downwardly relative to theadjacent element and into concentric relation to said member to raisesaid load carrier longitudinally of and independently of said innerguides.

16. A truck as claimed in claim 15 wherein said concentrically relatedelements, following the movement of said load carrier relative to saidinner guides, are relatively moved by the continued supply of fluidpressure to simultaneously raise the inner guides and said load carrierupwardly to position the latter at a higher level.

17. In an industrial truck having a pair of outer vertical guides, apair of inner vertical guides slidably mounted on said outer guides andmovable endwise thereof, an elevating member slidably mounted on saidinner guides, a hydraulically operated mechanism consisting of aplurality of axially related and relatively movable concentriccylinder-piston elements one of which is provided with diametricallyrelated reeving devices, flexible members engaging said reeving devicesand connected to said elevating member, a second element being mountedon the truck frame and a third element being connected to said innerguides, a supply of fluid under pressure having a controlling valve forsaid mechanism arranged to first move that element provided with saidreeving devices endwise to raise said elevating member longitudinallyand independently of said inner guides to a predetermined level andthereafter operate said third member relative to said second member toraise said inner guides and said elevating member, whereby the latter israised to a higher level.

18. In a truck having a pair of substantiall vertical main guidessupported on the truck frame, a pair of secondary guides slidablymounted on the main guides for movement endwise thereof, a load carrierslidably mounted on said secondary guides, a hydraulically operatedmechanism for raising said carrier and consisting of an elongated membermounted on the truck frame between and parallel to said guides, aplurality of concentrically related relatively movable elements disposedaxially of said member, one of said elements being provided withdiametrically disposed outwardly extending shafts, reeving devicesmounted on said shafts, flexible members engaging said reeving devicesand connected to said carrier, and valve controlled fluid pressuresupply means connected to said mechanism and arranged to initially applypressure to that element of said mechanism provided with said reevingdevices to move said element axially of said elongated member and raisesaid carrier relative to said guides and thereafter move said carrierand said secondary guides relative to said main guides.

19. In an industrial truck having a pair of outer vertical guides, apair of inner vertical guides slidably mounted on said outer guides andmovable endwise thereof, an elevating member slidably mounted on saidinner guides, a

hydraulically operated mechanism consisting of a plurality of axiallyrelated and relatively movable concentric cylinder-piston elements, oneof which is provided with diametrically related reeving devices,flexible members engaging said reeving devices and connected to saidelevating member, a second element being mounted on the truck frame anda third element having at its upper end an end wall, to which fluidpressure is applied, connected to said inner guides, a supply of fluidunder pressure having a controlling valve for said mechanism arranged tofirst move that element provided with said receiving devices endwise toraise said elevating member longitudinally and independently of saidinner guides to a predetermined level and thereafter, due to fluidpressure on said end wall, operate said third member relative to saidsecond member to raise said inner guides and said elevating member,whereby the latter is raised to a higher level.

NATHAN M. LAWLESS.

REFERENCES CITED UNITED STATES PATENTS Name Date Schroeder Apr. 12, 1950Number

